Method of making suede-like plastic

ABSTRACT

A suede-like plastic material is prepared from a fabric coated with a cellular vinyl chloride resin. The surface of the resin material is characterized by an undulating or irregular surface which is generally uniformly composed of tensile ruptured cells giving the surface a suede-like appearance approaching that of natural suede leather. The suede material is prepared by the bonding together of surfaces of two resin layers of differing relative tensiles, at least one layer being gelled blowable vinyl chloride resin, which are subsequently heated to form a cellular laminate. The laminate is then delaminated by stripping the layers apart along the bonding plane between the surface, the stripping occurring by the tensile discontinuity of the original bonding or lamination process thereby imparting a natural suedelike material to at least one delaminated surface of the resin layers. The suede-like surface can also be prepared by forming a temperature gradient across a section of the foam and rupturing the cells.

United States Patent [1 1 [111 3,709,752 Wistozk et al. 1 Jan. 9 1973[54] METHOD OF MAKING SUEDE-LIKE 7,229 5/1963 Japan ..l61/159 PLASTICPrimary Examiner-William A. Powell [75] lnvemors' z i gz mg gwg g ggPeter Attorney-Martin Kirkpatrick [73] Assignee: Pandel-Bradford, Inc.,Lowell, [57] ABSTRACT Mass' A suede-like plastic material is preparedfrom a fabric [22] Filed: Jam 20, 1971 coated with a cellular vinylchloride resin. The surface 1 L of the resin material is characterizedby an undulating [2 1 App No l08193 or irregular surface which isgenerally uniformly com- Related US. Application Data posed of tensileruptured cells giving the surface a suede-like appearance approachingthat of natural [63] 58:55:12? of 1967 suede leather. The suede materialis prepared by the bonding together of surfaces of two resin layers ofdiffering relative tensiles, at least one layer being gelled [52]blowable vinyl chloride resin, which are subsequently 16l/160 161/164heated to form a cellular laminate. The laminate is 51 Int. Cl ..B32b5/18 83 2b 31/00 laminated by stripping the layers [58] Field of 225/1 5the bonding plane between the surface, the stripping 344 2 occurring bythe tensile discontinuity of the original 161/62l67 bonding orlamination process thereby imparting a natural suede-like material to atleast one delaminated [56] References Cited surface of the resin layers.

The suede-like surface can also be prepared by form- UNITED STATESPATENTS ing a temperature gradient across a section of the 3,123,5083/1964 Waugh ..l56/78 foam and rupturing the cells. 3,04l,l93 6/1962Hamway et al ..ll7/ll 30 Claims, 4 Drawing Figures FOREIGN PATENTS 0RAPPLICATIONS 3,479 6/1962 Japan "161/159" METHOD OF MAKING SUEDE-LIKEPLASTIC This application is a continuation of application Ser. No.661,459, filed Aug. 17, 1967, now abandoned.

BACKGROUND OF THE INVENTION Normally the surface of plastic sheetingsuch as vinyl chloride resin sheet is smooth and often shiny inappearance. It is often desirable to prepare plastic surfaces which havea different appearance, feel or texture such as for uses as a decorativecovering or for utilitarian purposes. It is particularly desirable toprepare a soft flexible plastic coated fabric which has the feel andappearance of more expensive suede-like material such as leather. in thepast attempts to obtain such a plastic suede-like material and asuede-like surface have not been wholly successful. Some methods havebeen directed toward separate or additional treatments of the surface ofthe plastic material to obtain the desired appearance. Such additionaltreatment has often resulted in a product of less than acceptableappearance, while additional treatment has resulted in a more expensiveoperation than commercially acceptable. For example, U.S. Pat. No.3,041,193 issued June 26, 1967, to e.g., Hamway et al, describes amethod of making a suede-like plastic sheeting material by preparing acellular polyvinyl coating on a fabric and then abrading the exposedsurface of the cellular layer to produce a suede-like finish. The patentis hereby incorporated by reference in its entirety in this application.Another technique which also requires an abrasion operation is set forthin U.S. Pat. No. 3,312,586 issued Apr. 4, 1967, to T.W. Barlow.

SUMMARY OF THE INVENTION Our invention relates to a suede-like plasticmaterial composed of a sheet material having a cellular plastic coatingthereon, the surface of the coating characterized by an undulating orirregular surface which is generally uniformly composed of ruptured opencells with short fiber-like resin surface which presents a suedeappearance to the surface and which material is flexible and has a softhand. The exposed cell edges are rough and irregular and thereforeprovides the fiberlike characteristic similar to leather.

Our material is prepared by bonding together the resin surfaces of afirst and a second resin coated sheet material, at least one layer,thereof, containing a blowing agent and, thereafter heating the bondedlaminate to decompose the blowing agent to create one or two cellularlayers in the laminate. The laminate is then delaminated by strippingapart the bonded surfaces of the first and second sheet materials toprovide the finished product which is a sheet material having a cellularlayer thereon with a suede-like surface. ln general the strippingoperation occurs across the entire planar surface of the cellular layerwherein a tensile gradient or a plane of tensile discontinuity occursbetween the surface of the first and second sheet material. Thiscontrolled delamination provides for the controlled rupture of the cellsof the one or both cellular layers to impart an irregular or undulatingnatural suede-like sur face to the product. The tensile gradient ordiscontinuity between the bonded surface may be created by a number ofvarious methods including for example, degree of expansion, variation inthe resin formulation and composition of the resin layers such as thevariation of silica content, the type and molecular weight of the resin,and the amount and type of plasticizer employed. Other methods includewithout limitation the use of physical methods such as employing atemperature gradient across the laminate layers and the temperatures atwhich the lamination and/or delamination occurs. Alternately, anadhesive-coated substrate is applied to a cellular layer. The adhesivechosen is one with sufficient internal strenghth to remove the top ofthe cellular layer upon delamination thereby providing the open-celledsuede-like structure.

Various types of suede-like and other rough finishes may be imparted toone or more of the surfaces of the cellular sheet material by varyingthe tensile or fiberforming properties of the resin or the temperatureat which the delamination occurs. For example, our stripping operationpermits a more natural undulating surface effect to be obtained sincethe stripping operation unlike a synthetic cutting operation or anabrasion operation provides a random irregular surface which may vary inthickness from a plane surface for example, from 1 to 5 mils. This is tobe contrasted with an abrasion operation for example, wherein theabrading wire wheel gives a generally level regular surface across theentire fabric and destroys and reduces a portion of the surface in theoperation. In our method, both surfaces which have been split open bytensile rupture have the desirable suede-like surface. Further byvarying the temperature at which controlled delamination occurs, theamount of short fibers present and surface appearance of our materialmay be varied. Where a lower temperature of delamination is employedthere is a tendency for the resin surfaces to form more a fibroussurface, that is the resin tends to stretch more before breaking apartfrom the plane of tensile discontinuity or the bonding plane between thefirst and second sheet materials. At higher temperatures, there isusually less tendency for the resin fibers to be pulled out in length,since the thermoplastic fibers tend to break quickly and, therefore,form short fiber lengths on the surface thereby giving a differentappearance to the sheet material surface. Of course, the selection ofthe particular temperature or temperature range to use in the strippingoperation depends upon the type surface desired and character of theresin and formulation employed.

One preferred method of preparing the material is to employ a first andsecond sheet material both of which contain a blowable plastic layerthereon and both of different thicknesses, so that upon the subsequentformation of the cellular layers and the controlled delamination, bothportions of the laminate, that is, the first and second sheet materials,both have surfaces of a suede-like appearance.

The term tensile ruptured," as used therein is intended to refer to thecleavage of the cells and the weakest structural point to form aragged-edged, irregularly-shaped, open cells providing a randomirregular surface.

It is, therefore, an object of our invention to provide a new and uniquecellular plastic sheet material which is soft and flexible and has asurface appearance of a natural suede-like finish.

Another object of our invention is to provide a method or preparing asuede-like plastic sheet material and particularly a cellular vinylchloride resin coated fabric material having a suede-like surface byboth a plastisol and calendering technique.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a schematic illustration ofone method of preparing a resin coated fabric in accordance with ourinvention which fabric has a suede-like cellular surface.

FIG. 2a-h illustrates cross-section views of enlarged fragmentarymaterials at various steps of the process as shown in FIG. 1.

.FIG. 3 is a schematic illustration of another method of preparingsuede-like materials of our invention by the use of calendered resinsheets. I

FIG. 4a and b, is a representative cross-section view of an enlargedfragmentary material as prepared by the method set forth in FIG. 3.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A cellular vinyl chloride resincoated fabric having a suede-like cellular surface may be prepared bythe use of resin formulations such as those set forth in Tables 1 and 2,hereafter, by the process shown in FIG. 1, while a process employingcalendered sheets of vinyl chloride resin is shown more particularly inFIG. 3. In the method as shown in FIG. 1, a backing sheet of a thininexpensive casting type paper 12 has a plastisol cast onto the surfaceat a thickness of approximately two to ten mils for example, three tosix mils. The vinyl chloride resin plastisol from a source 14 is cast orcoated onto the surface by the use of doctor blade 16 or other coatingtechnique. The typical plastisol formulation is set forth in Table 1 andis composed primarily of a low or medium molecular weight resin with anexcess of plasticizer that is it is compounded to exhibit low hot filmstrength. The backing sheet 12 with the thin plastisol coating 18 isthen passed through an oven 20 and heated to a temperature sufficient togel and/or blow the vinyl chloride resin; typically, a temperature of255-350 F., e.g. 300 F. The time in the oven is adjusted to provide asubstantially tack-free coating surface to the gelled layer 18. Afterremoval from oven 20, another vinyl chloride resin plastisol formulationsuch as that set forth in Table II, is cast coated from a source 22 byadoctor blade 24 to form a relatively thick layer 26 on the surface ofthe gelled vinyl chloride layer 18. The plastisol layer 26 is cast in athickness of from about to 50 mils, preferably to 30 mils, and has beencompounded employing a high molecular weight polymer with lowerplasticizer levels so as to provide a I higher film hot strength thanlayer 18. This formulation is selected to provide the coated layerhaving the more natural suede-like appearance.

azodicarbonamide Stabilizer (Actofoam-R-3 mixture of inc and potamiumfatty acid salts in dioctylphthalate 0.75 TOTAL 177.50

I. A trademark of Firestone 2. A trademark of Goodyear 3. A trademark ofMonsanto 4. and 5. A trademark of National Polyehemicals, Inc.

TABLE II INGREDIENTS Parts By Weight Vinylchldride resin dispersiongrade (GEON 121 37.0 (GEDN 222 l7.0 (PLIOVIC W0 9.0 Diluent resin(PLIOVIC M-) 35.0 Plasticizer (nonyl octyl phthalate 12.0 a) monomeric(Butyl dioctyl phthalate 10.0 (diisoocyl phthalate 29.0 b) polymeric(SANTICIZER 845 3.0 blowing agent (KEMPORE 200) azodicarbonamideStabilizer activator (ACTOFOAM 11-3) 2.0 TOTAL 1 54.0

I. and 2. A trademark of Goodrich 3. A trademark of Goodyear 4. Atrademark of Goodyear 5. A trademark of Monsanto 6. and 7. A trademarkof National Polychemicals, Inc.

Backing sheet 12 with gel layer 18 and plastisol layer 26 is then passedto a hot air oven 28 wherein the layer 26 is heated to a temperature, asin oven 20. that is sufficient to gel the plastisol or decompose theblowing agent therein. The temperature of oven 28 is typically from 300to 400 F. Of course, the desired vinyl chloride resin layer 26 may bethe same or a differentcolor than layer 18 to provide any desiredcontrast. The same resins or plasticizers may also be employed in bothlayers provided that the amounts or other compounds are employed toprovide formulations with different properties. Where similarformulations are used then a temperature gradient may be used to providestrippable layers.

The gelling time in oven 28 should not be sufficient to provide atack-free coating in the surface of layer 26. Layer 18 is normallygelled to a tack-free surface coating so that there is a reduction ofmigration of the layer 26 into layer 18 which may blur the plane oftensile discontinuity and the controlled delamination which is laterdesired. However, the top surface of layer 28 should be slightly tackyafter emerging from oven 26. A backing fabric 30 such as a woven cottonor non-woven material is then placed on the top surface of the tackylayer 26 and pressed into adhering contact with the surface. If the topsurface of layer 26 is essentially tackfree,.the fabric 30 may notadhere to the surface, while if layer 28 has been insufficiently gelled,a porous cotton fabric might wick up a portion of the plastisol orplasticizer and become discolored.

The laminate comprising backing sheet 12, gel layer 18, gel layer 26,and backing fabric 30 is then heated in oven 34 to a temperaturesufficient to decompose the blowing agent in layers 18 and 26 to createseveral blown or cellular layers 32 and 33 which layers are bondedtogether by surface of tensile discontinuity 35. Typically, the laminateshould be heated to a temperature of from about 375 to 435 F untilsubstantially all of the blowing agents has decomposed.

The cellular laminate, after removal from oven 34 is then delaminated bystripping the backing fabric 30 with cellular layer 32 from cellularlayer 33 and the backing sheet 12. The stripping operation may beaccomplished by a rapid or gradual pulling apart of the respectivecoated sheet materials. In the process described, the stripping iscarried out just after emersion of the laminate from oven 34 so that thetemperature of stripping is approximately 275 F to 350 F. Of course, ifdesired, the laminate may be stored as the gelled laminate or blownlaminate and the stripping operation carried out as required. As thebacking fabric is pulled in one direction and the backing sheet 12 isanother, the laminate will delaminate along the general planar surfaceof contact between layer 33 and 32 where there is tensile gradient ortensile discontinuity between the resin layers created by theformulations used. The higher hot resin strength of the layer 26 willcreate a natural suede-like open rupture cell surface on the cellularlayer 32 while surface of cellular layer 33 may be more grainy innature.

FIG. 2 shows representative cross-sectional views of the backing sheetlayer 12, layer 18 and 26, backing fabric 30, cellular layers 32 and 33as the material is processed through the corresponding steps of FIG. 1.FIGS. 2g and h illustrate the irregular surfaces and 42 as prepared bythe controlled stripping which surface 40 represents a suede-likeappearance.

Our invention has been described in particular employing a backingfabric and a backing sheet, however, it is recognized that the backingsheet and backing fabric may be the same or different materials. Forexample, woven and non-woven natural and synthetic sheet materials maybe employed as desired, such as woven sheet materials like cotton, wooland silk, hemp, felt, or knitted materials or fabrics which areextensible and stretchable in one or more directions. Fibrous materialswould include glass fibers, kraft paper, rayon,

nylon, polyethylene, polypropylene, urethanes, acrylics or othersynthetic fibrous material such as polyesters or combinations thereof.In particular our invention has been illustrated by employing smoothsheet material, however, it is also recognized that the backing sheetand/or fabric may be embossed, for example, having a decorative designthereon, to impart a decorative suede-like surface appearance. Further,the sheet material may have one or more other coatings thereon such asprimer or bonding or decorative coatings. In the process described, thecellular-coated backing sheet 38 which has only a thin cellular layerthereon may then be reused several times as the backing sheet 12 in theprocess or if desired, it may be employed for covering or decorative orother purposes where a suede-like or roughened finish is desirable.

FIG. 3 is a schematic illustration of a process employing calenderedvinyl chloride resin sheet material. For example, the calender sheetmaterial employed in this embodiment of our invention may be thatdescribed in the US. Pat. No. 2,964,799 issued Dec. 20, I960 to PE.Roggi et al which patent is hereby incorporated by reference in itsentirety in this application. As shown, a thin calendered polyvinylchloride sheet containing a blowing agent for example a calendered sheetprepared as in Table I is unrolled and one surface heated, such as byinfrared heaters 52, to a soft condition, but insufficiently todecompose the blowing agent therein. The tacky surface is then placed incontact with the surface of the backing sheet 54 to adhere thereto afterpassing through a pair of contacting rollers. Another polyvinyl chloridecalendered sheet material 58 formulated as in Table 2 also have its onesurface heated to a tacky condition by infrared heaters 56 which surfaceis then pressed against the opposite surface through calender rolls tocalender sheet 50. Of course if desired, the top surface of sheet 50could be treated or both surfaces heated prior to bonding of sheets 50and 58.

Also, 58 may be a calendered laminate comprising a backing fabric havinga calendered sheet secured thereto of a vinyl chloride resin containinga blowing agent or as illustrated a separate backing fabric 61 may bepassed into contact with the top surface of the calendered vinylchloride resin 58 after rendering the surface tacky through heaters 59.The bonded laminate of backing fabric. 61, calendered sheet 58,calendered sheet 50 and backing fabric 54 is then passed to an oven 60wherein the laminate is heated to a temperature of about 400 to 425 F.to decompose the blowing agents in both calendered sheets layers tocreate blown or cellular layers 62 and 64. Upon emergence from the ovenat a temperature of about 340-360 F backing fabric 61 with layer 64stripped away across substantially the surface plane of contact frombacking fabric 54 and cellular layer 62 to provide two separate cellularcoated fabrics each having a suede-like cellular surface finish. v

FIG. 4 is a cross-sectional representation of the new suede-likematerial prepared by the calender method as set forth in FIG. 3 whereinthe suede-like surface 66 and 68 are similar in nature. In thisillustration the calendered sheets are approximately equal in thickness,but as before of different resin strength so that at the strippingtemperature used, there is created a tensile gradient across the surfaceof bonding thereby permitting the controlled stripping. However, in thiscase two separate products are obtained, one having a mirror imagesuede-like finish relative to the other.

In general, the ratio of thickness of the layer may vary from 1:10 to10:1 preferably 5:1 to 1:5. Our invention has been illustrated withparticular resin formulations, however, as set forth in both Hemway eta1 and Roggi et al patents, various resins as well as monomeric andpolymeric plasticizers blowing agents, fillers and other materials maybe employed in such resin formulations. In particular, our invention hasbeen described wherein both the backing sheet and the fabric sheet haveemployed blowable vinyl chloride resin layers. However, it is alsorecognized that the backing sheet need not have a blowable vinylchloride resin layer, but that a vinyl chloride resin with or without ablowing agent or another resin coating may be employed on the backingsheet to provide the control stripping and delamination from thecellular vinyl chloride resin layer making up the suede-like product.The selection of the resin formulation to employ on the backing sheetrequires that the resin form a bond with the blowable resin formulationfrom which it is to be later stripped, yet the bond must be such as tobe easily stripable therefrom after blowing of the blowable layeressentially along the plane of bonding. Various thermoplastic ortherrnosetting resins may accordingly then be used on the backing sheetwith or without the blowing agents to provide the suede coated materialsof this invention.

What is claimed is:

l. A method of preparing a sheet material having a suede-like surfaceappearance, which method comprises:

a. laminating together the thermoplastic resin surfaces of a first andsecond laminate to form a sandwich laminate each laminate comprising asheet material having a thermoplastic resin layer bonded thereto, thelayer of the first laminate containing a blowing amount of a blowingagent;

decomposing the blowing agent in the first laminate to create a cellularthermoplastic resin foam structure in the first layer;

c. providing a random irregular surface plane of tensile discontinuityin said sandwich laminate; and

d. delaminating the first laminate from the second laminate by strippingthe laminates apart substantially along the surface plane between thebonding surface of the cellular layer of the first laminate and thethermoplastic resin surface of the second laminate, thereby providing alaminate containing a surface composed of tensile-ruptured cells of asuede-like surface appearance.

2. The method of claim 1 wherein a temperature gradient is maintainedacross the sandwich laminate during delamination.

3. The method of claim 1 wherein the second laminate comprises acellular thermoplastic resin layer.

4. The method of claim 1 wherein the thermoplastic resins of the firstand second laminate layers are of similar chemical composition but varyin molecular weight.

5. The method of claim 1 wherein the thermoplastic resin of the firstand second laminates is a vinyl chloride resin.

6. The method of claim 1 wherein the ratio of the thickness of the firstthermoplastic resin layer to the second thermoplastic resin layer variesfrom about 10 to l to l to 10 and wherein the temperature ofdelamination ranges from about 250 to 450 F.

7. A method of preparing a sheet material having a suede-like surfaceappearance which method comprises:

a. bonding together the thermoplastic resin surfaces of a first andsecond laminate to form a sandwich laminate, each laminate comprising asheet material having a thermoplastic resin layer bonded thereto, thelayer of the first laminate comprising a vinyl chloride resin and ablowing agent;

heating the sandwich laminate to a temperature sufficient to create afirst cellular foam layer; and

c. delaminating the first laminate from the second laminate by strippingthe laminates apart along the surface plane between the bonding surfaceof the cellular layer of the first laminate and the thermoplastic resinsurface of the second laminate, the temperature of stripping selected toprovide a plane of tensile discontinuity between the first and secondlaminates, thereby providing a first and second laminate, one of whichhas a cellular layer of a suede-like surface appearance.

8. The method of claim 7 wherein the second laminate also comprises avinyl chloride resin layer and a blowing agent and wherein the sandwichlaminate is heated to a temperature sufiicient to create a two-layercellular structure. 7

9. The method of claim 8 wherein the vinyl chloride resins in the firstand second laminate are compounded to provide a difference in hotstrength at the temperature of stripping.

10. The method of claim 7 wherein the temperature of stripping rangesfrom about 250 to 450 F.

11. The method of claim 7 wherein the thickness of the layer of thefirst laminate ranges from about 2 to 50 mils while the thickness of thesecond laminate ranges from about 1 to 10 mils.

12. The method of claim 7 wherein the second laminate comprises anoncellular vinyl chloride resin layer.

13. The method of claim 12 wherein the vinyl chloride resin in the firstand second laminate are compounded to provide a difference in hotstrength between the surfaces of the resin layers at the temperature ofstripping.

14. The method of claim 7 which includes maintaining a temperaturegradient across the laminate layers.

al of the first laminate comprises a woven fabric and the sheet materialof the second laminate comprises a paper sheet.

18. The method of claim 7 wherein the first and second laminatescomprises a vinyl chloride resin and the laminates are bonded togetherby casting vinyl chloride resin plastisol layers, one on top of theother.

19. The method of claim 7 wherein the first and second laminatescomprise a vinyl chloride resin and the laminates are bonded together byheating the surfaces of calendered vinyl chloride resin sheets andpressing the heated surfaces into contact.

20. A method of preparing a sheet material having a natural suede-likesurface appearance which method comprises:

a. coating a thin coating of from about 1 to l0 mils of thickness of avinyl chloride plastisol onto a first sheet :material, said plastisolcontaining a small amount of a blowing agent;

b. heating the first plastisol layer to a temperature sufficient to gelthe vinyl chloride resin to a tackfree surface, but insufficient todecompose substantially the blowing agent therein;

c. casting a coating of from about 5 to 30 mils of a second plastisolonto the surface of the gelled first plastisol layer;

. heating the second plastisol layer to a temperature sufficient to gelthe layer and to provide a tacky upper surface to the second vinylchloride plastisol layer;

e. bonding to the tacky surface of the second plastisol layer a secondsheet material to form a sandwich laminate;

f. heating the sandwich laminate so formed to a temperature sufficientto provide a first cellular foam layer; and

g. delaminating the sandwich laminate by stripping the first cellularlayer from the second layer, the stripping occurring along the bondingplane between the bonding surface of the first and second layers, thetemperature of stripping selected to provide a plane of tensilediscontinuity between the respective layers thereby providing a firstand second laminate, one of which has a cellular layer of a suede-likesurface appearance.

21. A method of preparing a sheet material having a suede-like surfaceappearance, which method comprises:

providing a laminate structure having two outer sheet materials, one ofwhich is a paper sheet and the other is a woven sheet, and at least oneinner cellular foam thermoplastic resin layer;

. establishing a temperature gradient providing a random irregularsurface plane of tensile discontinuity in the cellular layer; and

stripping the two sheet materials apart along said plane to tensilerupture the inner cellular layer, the temperature of stripping rangingfrom about 250 F to 450 F, thereby providing two sheet materials, eachof which are characterized by an undulating suede-like surfaceappearance.

22. The method of claim 21 wherein the resin layers comprise plasticizedvinyl chloride resin layers.

23. The method of claim 21 wherein the temperature of stripping rangesfrom about 275 F to 350 F.

24. The method of claim 21 which includes preparin g the laminatestructure by the steps of:

a. casting a first thin layer of a vinyl chloride resin plastisol ontothe surface of the woven sheet material;

b. heating the first layer to a temperature to gel] the resin layer;

c. casting a second thin layer of a vinyl chloride resin plastisolcontaining a blowing agent onto the gelled surface of the first layer;

d. placing a paper sheet material onto the surface of the second layer;

e. heating the first and second layers in an oven to fuse the resinlayers and to form at least one cellular layer, thereby forming alaminate structure; and

f. stripping the sheet materials apart on emergence of the laminatestructure from the heating oven.

25. A method of preparing a sheet material having a suede-like surfaceappearance, which method comprises:

providing a laminate structure having two outer sheet materials and atleast one inner cellular foam plastic resin layer, said laminatestructure having a random irregular surface plane of tensilediscontinuity in the cellular layer between and spaced from the twoouter sheet materials of the laminate; and

stripping the two sheet materials apart along said plane to tensilerupture the inner cellular layer while maintaining such tensilediscontinuity to control the nature of the resulting suede surface,thereby providing two sheet materials, at least one of which ischaracterized by an undulating suedelike surface formed by tensileruptured raggededged, irregularly-shaped open cells of said cellularlayer. 26. The method of claim 25 wherein the cellular resin layer is aplasticized vinyl chloride resin layer.

27. The method of claim 25 wherein said tensile discontinuity isprovided by establishing a tensile gradient between two inner layers.

28. The method of claim 25 wherein each of said two sheet materials ischaracterized by an undulating suede-like surface formed by tensileruptured raggededged, irregularly-shaped open cells of said cellularfoam layer.

29. The method of claim 25 wherein said tensile discontinuity isprovided by establishing a temperature gradient in the cellular layer.

30. The method of claim 29 which includes stripping the two sheetmaterials apart at a temperature of from about 250 F to 450 F.

UNITED STATES PATENT OFFECE @ETEFECATE @F RRECTFN Patent No. 709 9 1 atJanuary '9 1973 inventofls) Reuben wisotzky and R1 chard E. Petersen Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

In the title page, line [75], the name of the inventor Reuben Wistozky"shou1d be amended to read --Reuben wisotzky.

Signed and sealed this 29th day of May 1-973.

(SEAL) Attest:

EDWARD M.FLETCHER,JR. ROBERT GOTTSCHALK Attesting Officer Commissionerof Patents FORM PO-1050 (10-69) USCOMM-DC some-p695- i [1.5. GOVERNMENTPRINTING OFFICE i969 0-366-334.

2. The method of claim 1 wherein a temperature gradient is maintainedacross the sandwich laminate during delamination.
 3. The method of claim1 wherein the second laminate comprises a cellular thermoplastic resinlayer.
 4. The method of claim 1 wherein the thermoplastic resins of thefirst and second laminate layers are of similar chemical composition butvary in molEcular weight.
 5. The method of claim 1 wherein thethermoplastic resin of the first and second laminates is a vinylchloride resin.
 6. The method of claim 1 wherein the ratio of thethickness of the first thermoplastic resin layer to the secondthermoplastic resin layer varies from about 10 to 1 to 1 to 10 andwherein the temperature of delamination ranges from about 250* to 450*F.
 7. A method of preparing a sheet material having a suede-like surfaceappearance which method comprises: a. bonding together the thermoplasticresin surfaces of a first and second laminate to form a sandwichlaminate, each laminate comprising a sheet material having athermoplastic resin layer bonded thereto, the layer of the firstlaminate comprising a vinyl chloride resin and a blowing agent; b.heating the sandwich laminate to a temperature sufficient to create afirst cellular foam layer; and c. delaminating the first laminate fromthe second laminate by stripping the laminates apart along the surfaceplane between the bonding surface of the cellular layer of the firstlaminate and the thermoplastic resin surface of the second laminate, thetemperature of stripping selected to provide a plane of tensilediscontinuity between the first and second laminates, thereby providinga first and second laminate, one of which has a cellular layer of asuede-like surface appearance.
 8. The method of claim 7 wherein thesecond laminate also comprises a vinyl chloride resin layer and ablowing agent and wherein the sandwich laminate is heated to atemperature sufficient to create a two-layer cellular structure.
 9. Themethod of claim 8 wherein the vinyl chloride resins in the first andsecond laminate are compounded to provide a difference in hot strengthat the temperature of stripping.
 10. The method of claim 7 wherein thetemperature of stripping ranges from about 250* to 450* F.
 11. Themethod of claim 7 wherein the thickness of the layer of the firstlaminate ranges from about 2 to 50 mils while the thickness of thesecond laminate ranges from about 1 to 10 mils.
 12. The method of claim7 wherein the second laminate comprises a noncellular vinyl chlorideresin layer.
 13. The method of claim 12 wherein the vinyl chloride resinin the first and second laminate are compounded to provide a differencein hot strength between the surfaces of the resin layers at thetemperature of stripping.
 14. The method of claim 7 which includesmaintaining a temperature gradient across the laminate layers duringdelamination.
 15. The method of claim 7 wherein the temperature ofdelamination ranges from about 275* F to 350* F.
 16. The method of claim7 wherein the ratio of the thickness of the first and second laminatesranges from about 10:1 to 1:10.
 17. The method of claim 7 wherein thesheet material of the first laminate comprises a woven fabric and thesheet material of the second laminate comprises a paper sheet.
 18. Themethod of claim 7 wherein the first and second laminates comprises avinyl chloride resin and the laminates are bonded together by castingvinyl chloride resin plastisol layers, one on top of the other.
 19. Themethod of claim 7 wherein the first and second laminates comprise avinyl chloride resin and the laminates are bonded together by heatingthe surfaces of calendered vinyl chloride resin sheets and pressing theheated surfaces into contact.
 20. A method of preparing a sheet materialhaving a natural suede-like surface appearance which method comprises:a. coating a thin coating of from about 1 to 10 mils of thickness of avinyl chloride plastisol onto a first sheet material, said plastisolcontaining a small amount of a blowing agent; b. heating the firstplastisol layer to a temperature sufficient to gel the vinyl chlorideresin to a tack-free surface, but insufficient to decomposesubStantially the blowing agent therein; c. casting a coating of fromabout 5 to 30 mils of a second plastisol onto the surface of the gelledfirst plastisol layer; d. heating the second plastisol layer to atemperature sufficient to gel the layer and to provide a tacky uppersurface to the second vinyl chloride plastisol layer; e. bonding to thetacky surface of the second plastisol layer a second sheet material toform a sandwich laminate; f. heating the sandwich laminate so formed toa temperature sufficient to provide a first cellular foam layer; and g.delaminating the sandwich laminate by stripping the first cellular layerfrom the second layer, the stripping occurring along the bonding planebetween the bonding surface of the first and second layers, thetemperature of stripping selected to provide a plane of tensilediscontinuity between the respective layers thereby providing a firstand second laminate, one of which has a cellular layer of a suede-likesurface appearance.
 21. A method of preparing a sheet material having asuede-like surface appearance, which method comprises: providing alaminate structure having two outer sheet materials, one of which is apaper sheet and the other is a woven sheet, and at least one innercellular foam thermoplastic resin layer; establishing a temperaturegradient providing a random irregular surface plane of tensilediscontinuity in the cellular layer; and stripping the two sheetmaterials apart along said plane to tensile rupture the inner cellularlayer, the temperature of stripping ranging from about 250* F to 450* F,thereby providing two sheet materials, each of which are characterizedby an undulating suede-like surface appearance.
 22. The method of claim21 wherein the resin layers comprise plasticized vinyl chloride resinlayers.
 23. The method of claim 21 wherein the temperature of strippingranges from about 275* F to 350* F.
 24. The method of claim 21 whichincludes preparing the laminate structure by the steps of: a. casting afirst thin layer of a vinyl chloride resin plastisol onto the surface ofthe woven sheet material; b. heating the first layer to a temperature togell the resin layer; c. casting a second thin layer of a vinyl chlorideresin plastisol containing a blowing agent onto the gelled surface ofthe first layer; d. placing a paper sheet material onto the surface ofthe second layer; e. heating the first and second layers in an oven tofuse the resin layers and to form at least one cellular layer, therebyforming a laminate structure; and f. stripping the sheet materials aparton emergence of the laminate structure from the heating oven.
 25. Amethod of preparing a sheet material having a suede-like surfaceappearance, which method comprises: providing a laminate structurehaving two outer sheet materials and at least one inner cellular foamplastic resin layer, said laminate structure having a random irregularsurface plane of tensile discontinuity in the cellular layer between andspaced from the two outer sheet materials of the laminate; and strippingthe two sheet materials apart along said plane to tensile rupture theinner cellular layer while maintaining such tensile discontinuity tocontrol the nature of the resulting suede surface, thereby providing twosheet materials, at least one of which is characterized by an undulatingsuede-like surface formed by tensile ruptured ragged-edged,irregularly-shaped open cells of said cellular layer.
 26. The method ofclaim 25 wherein the cellular resin layer is a plasticized vinylchloride resin layer.
 27. The method of claim 25 wherein said tensilediscontinuity is provided by establishing a tensile gradient between twoinner layers.
 28. The method of claim 25 wherein each of said two sheetmaterials is characterized by an undulating suede-like surface formed bytensile ruptured raggeD-edged, irregularly-shaped open cells of saidcellular foam layer.
 29. The method of claim 25 wherein said tensilediscontinuity is provided by establishing a temperature gradient in thecellular layer.
 30. The method of claim 29 which includes stripping thetwo sheet materials apart at a temperature of from about 250* F to 450*F.